| 1 | #!/usr/bin/env python2
|
| 2 | from __future__ import print_function
|
| 3 |
|
| 4 | from _devbuild.gen import arg_types
|
| 5 | from _devbuild.gen.option_asdl import builtin_i
|
| 6 | from _devbuild.gen.runtime_asdl import (
|
| 7 | scope_e,
|
| 8 | cmd_value,
|
| 9 | AssignArg,
|
| 10 | )
|
| 11 | from _devbuild.gen.value_asdl import (value, value_e, value_t, LeftName)
|
| 12 | from _devbuild.gen.syntax_asdl import loc, loc_t, word_t
|
| 13 |
|
| 14 | from core import bash_impl
|
| 15 | from core import error
|
| 16 | from core.error import e_usage
|
| 17 | from core import state
|
| 18 | from core import vm
|
| 19 | from frontend import flag_util
|
| 20 | from frontend import args
|
| 21 | from mycpp.mylib import log, NewDict
|
| 22 | from osh import cmd_eval
|
| 23 | from osh import sh_expr_eval
|
| 24 | from data_lang import j8_lite
|
| 25 |
|
| 26 | from typing import cast, Dict, List, Optional, TYPE_CHECKING
|
| 27 | if TYPE_CHECKING:
|
| 28 | from core.state import Mem
|
| 29 | from core import optview
|
| 30 | from display import ui
|
| 31 | from frontend.args import _Attributes
|
| 32 |
|
| 33 | _ = log
|
| 34 |
|
| 35 | _OTHER = 0
|
| 36 | _READONLY = 1
|
| 37 | _EXPORT = 2
|
| 38 |
|
| 39 |
|
| 40 | def _PrintVariables(mem, cmd_val, attrs, print_flags, builtin=_OTHER):
|
| 41 | # type: (Mem, cmd_value.Assign, _Attributes, bool, int) -> int
|
| 42 | """
|
| 43 | Args:
|
| 44 | print_flags: whether to print flags
|
| 45 | builtin: is it the readonly or export builtin?
|
| 46 | """
|
| 47 | flag = attrs.attrs
|
| 48 |
|
| 49 | # Turn dynamic vars to static.
|
| 50 | tmp_g = flag.get('g')
|
| 51 | tmp_a = flag.get('a')
|
| 52 | tmp_A = flag.get('A')
|
| 53 |
|
| 54 | flag_g = (cast(value.Bool, tmp_g).b
|
| 55 | if tmp_g and tmp_g.tag() == value_e.Bool else False)
|
| 56 | flag_a = (cast(value.Bool, tmp_a).b
|
| 57 | if tmp_a and tmp_a.tag() == value_e.Bool else False)
|
| 58 | flag_A = (cast(value.Bool, tmp_A).b
|
| 59 | if tmp_A and tmp_A.tag() == value_e.Bool else False)
|
| 60 |
|
| 61 | tmp_n = flag.get('n')
|
| 62 | tmp_r = flag.get('r')
|
| 63 | tmp_x = flag.get('x')
|
| 64 |
|
| 65 | #log('FLAG %r', flag)
|
| 66 |
|
| 67 | # SUBTLE: export -n vs. declare -n. flag vs. OPTION.
|
| 68 | # flags are value.Bool, while options are Undef or Str.
|
| 69 | # '+', '-', or None
|
| 70 | flag_n = (cast(value.Str, tmp_n).s if tmp_n and tmp_n.tag() == value_e.Str
|
| 71 | else None) # type: Optional[str]
|
| 72 | flag_r = (cast(value.Str, tmp_r).s if tmp_r and tmp_r.tag() == value_e.Str
|
| 73 | else None) # type: Optional[str]
|
| 74 | flag_x = (cast(value.Str, tmp_x).s if tmp_x and tmp_x.tag() == value_e.Str
|
| 75 | else None) # type: Optional[str]
|
| 76 |
|
| 77 | if cmd_val.builtin_id == builtin_i.local:
|
| 78 | if flag_g and not mem.IsGlobalScope():
|
| 79 | return 1
|
| 80 | which_scopes = scope_e.LocalOnly
|
| 81 | elif flag_g:
|
| 82 | which_scopes = scope_e.GlobalOnly
|
| 83 | else:
|
| 84 | which_scopes = mem.ScopesForReading() # reading
|
| 85 |
|
| 86 | if len(cmd_val.pairs) == 0:
|
| 87 | print_all = True
|
| 88 | cells = mem.GetAllCells(which_scopes)
|
| 89 | names = sorted(cells) # type: List[str]
|
| 90 | else:
|
| 91 | print_all = False
|
| 92 | names = []
|
| 93 | cells = {}
|
| 94 | for pair in cmd_val.pairs:
|
| 95 | name = pair.var_name
|
| 96 | if pair.rval and pair.rval.tag() == value_e.Str:
|
| 97 | # Invalid: declare -p foo=bar
|
| 98 | # Add a sentinel so we skip it, but know to exit with status 1.
|
| 99 | s = cast(value.Str, pair.rval).s
|
| 100 | invalid = "%s=%s" % (name, s)
|
| 101 | names.append(invalid)
|
| 102 | cells[invalid] = None
|
| 103 | else:
|
| 104 | names.append(name)
|
| 105 | cells[name] = mem.GetCell(name, which_scopes)
|
| 106 |
|
| 107 | count = 0
|
| 108 | for name in names:
|
| 109 | cell = cells[name]
|
| 110 | if cell is None:
|
| 111 | continue # Invalid
|
| 112 | val = cell.val
|
| 113 | #log('name %r %s', name, val)
|
| 114 |
|
| 115 | if val.tag() == value_e.Undef:
|
| 116 | continue
|
| 117 | if builtin == _READONLY and not cell.readonly:
|
| 118 | continue
|
| 119 | if builtin == _EXPORT and not cell.exported:
|
| 120 | continue
|
| 121 |
|
| 122 | if flag_n == '-' and not cell.nameref:
|
| 123 | continue
|
| 124 | if flag_n == '+' and cell.nameref:
|
| 125 | continue
|
| 126 | if flag_r == '-' and not cell.readonly:
|
| 127 | continue
|
| 128 | if flag_r == '+' and cell.readonly:
|
| 129 | continue
|
| 130 | if flag_x == '-' and not cell.exported:
|
| 131 | continue
|
| 132 | if flag_x == '+' and cell.exported:
|
| 133 | continue
|
| 134 |
|
| 135 | if flag_a and val.tag() not in (value_e.BashArray,
|
| 136 | value_e.SparseArray):
|
| 137 | continue
|
| 138 | if flag_A and val.tag() != value_e.BashAssoc:
|
| 139 | continue
|
| 140 |
|
| 141 | decl = [] # type: List[str]
|
| 142 | if print_flags:
|
| 143 | flags = [] # type: List[str]
|
| 144 | if cell.nameref:
|
| 145 | flags.append('n')
|
| 146 | if cell.readonly:
|
| 147 | flags.append('r')
|
| 148 | if cell.exported:
|
| 149 | flags.append('x')
|
| 150 | if val.tag() in (value_e.BashArray, value_e.SparseArray):
|
| 151 | flags.append('a')
|
| 152 | elif val.tag() == value_e.BashAssoc:
|
| 153 | flags.append('A')
|
| 154 | if len(flags) == 0:
|
| 155 | flags.append('-')
|
| 156 |
|
| 157 | decl.extend(["declare -", ''.join(flags), " ", name])
|
| 158 | else:
|
| 159 | decl.append(name)
|
| 160 |
|
| 161 | if val.tag() == value_e.Str:
|
| 162 | str_val = cast(value.Str, val)
|
| 163 | decl.extend(["=", j8_lite.MaybeShellEncode(str_val.s)])
|
| 164 |
|
| 165 | elif val.tag() == value_e.BashArray:
|
| 166 | array_val = cast(value.BashArray, val)
|
| 167 | decl.extend(
|
| 168 | ["=",
|
| 169 | bash_impl.BashArray_ToStrForShellPrint(array_val, name)])
|
| 170 |
|
| 171 | elif val.tag() == value_e.BashAssoc:
|
| 172 | assoc_val = cast(value.BashAssoc, val)
|
| 173 | decl.extend(
|
| 174 | ["=", bash_impl.BashAssoc_ToStrForShellPrint(assoc_val)])
|
| 175 |
|
| 176 | elif val.tag() == value_e.SparseArray:
|
| 177 | sparse_val = cast(value.SparseArray, val)
|
| 178 | decl.extend(
|
| 179 | ["=",
|
| 180 | bash_impl.SparseArray_ToStrForShellPrint(sparse_val)])
|
| 181 |
|
| 182 | else:
|
| 183 | pass # note: other types silently ignored
|
| 184 |
|
| 185 | print(''.join(decl))
|
| 186 | count += 1
|
| 187 |
|
| 188 | if print_all or count == len(names):
|
| 189 | return 0
|
| 190 | else:
|
| 191 | return 1
|
| 192 |
|
| 193 |
|
| 194 | def _ExportReadonly(mem, pair, flags):
|
| 195 | # type: (Mem, AssignArg, int) -> None
|
| 196 | """For 'export' and 'readonly' to respect += and flags.
|
| 197 |
|
| 198 | Like 'setvar' (scope_e.LocalOnly), unless dynamic scope is on. That is, it
|
| 199 | respects shopt --unset dynamic_scope.
|
| 200 |
|
| 201 | Used for assignment builtins, (( a = b )), {fd}>out, ${x=}, etc.
|
| 202 | """
|
| 203 | which_scopes = mem.ScopesForWriting()
|
| 204 |
|
| 205 | lval = LeftName(pair.var_name, pair.blame_word)
|
| 206 | if pair.plus_eq:
|
| 207 | old_val = sh_expr_eval.OldValue(lval, mem, None) # ignore set -u
|
| 208 | # When 'export e+=', then rval is value.Str('')
|
| 209 | # When 'export foo', the pair.plus_eq flag is false.
|
| 210 | assert pair.rval is not None
|
| 211 | val = cmd_eval.PlusEquals(old_val, pair.rval)
|
| 212 | else:
|
| 213 | # NOTE: when rval is None, only flags are changed
|
| 214 | val = pair.rval
|
| 215 |
|
| 216 | mem.SetNamed(lval, val, which_scopes, flags=flags)
|
| 217 |
|
| 218 |
|
| 219 | class Export(vm._AssignBuiltin):
|
| 220 |
|
| 221 | def __init__(self, mem, errfmt):
|
| 222 | # type: (Mem, ui.ErrorFormatter) -> None
|
| 223 | self.mem = mem
|
| 224 | self.errfmt = errfmt
|
| 225 |
|
| 226 | def Run(self, cmd_val):
|
| 227 | # type: (cmd_value.Assign) -> int
|
| 228 | if self.mem.exec_opts.no_exported():
|
| 229 | self.errfmt.Print_(
|
| 230 | 'export builtin is disabled in YSH (shopt --set no_exported)',
|
| 231 | cmd_val.arg_locs[0])
|
| 232 | return 1
|
| 233 |
|
| 234 | arg_r = args.Reader(cmd_val.argv, locs=cmd_val.arg_locs)
|
| 235 | arg_r.Next()
|
| 236 | attrs = flag_util.Parse('export_', arg_r)
|
| 237 | arg = arg_types.export_(attrs.attrs)
|
| 238 | #arg = attrs
|
| 239 |
|
| 240 | if arg.f:
|
| 241 | e_usage(
|
| 242 | "doesn't accept -f because it's dangerous. "
|
| 243 | "(The code can usually be restructured with 'source')",
|
| 244 | loc.Missing)
|
| 245 |
|
| 246 | if arg.p or len(cmd_val.pairs) == 0:
|
| 247 | return _PrintVariables(self.mem,
|
| 248 | cmd_val,
|
| 249 | attrs,
|
| 250 | True,
|
| 251 | builtin=_EXPORT)
|
| 252 |
|
| 253 | if arg.n:
|
| 254 | for pair in cmd_val.pairs:
|
| 255 | if pair.rval is not None:
|
| 256 | e_usage("doesn't accept RHS with -n",
|
| 257 | loc.Word(pair.blame_word))
|
| 258 |
|
| 259 | # NOTE: we don't care if it wasn't found, like bash.
|
| 260 | self.mem.ClearFlag(pair.var_name, state.ClearExport)
|
| 261 | else:
|
| 262 | for pair in cmd_val.pairs:
|
| 263 | _ExportReadonly(self.mem, pair, state.SetExport)
|
| 264 |
|
| 265 | return 0
|
| 266 |
|
| 267 |
|
| 268 | def _ReconcileTypes(rval, flag_a, flag_A, blame_word):
|
| 269 | # type: (Optional[value_t], bool, bool, word_t) -> value_t
|
| 270 | """Check that -a and -A flags are consistent with RHS.
|
| 271 |
|
| 272 | Special case: () is allowed to mean empty indexed array or empty assoc array
|
| 273 | if the context is clear.
|
| 274 |
|
| 275 | Shared between NewVar and Readonly.
|
| 276 | """
|
| 277 | if flag_a and rval is not None and rval.tag() != value_e.BashArray:
|
| 278 | e_usage("Got -a but RHS isn't an array", loc.Word(blame_word))
|
| 279 |
|
| 280 | if flag_A and rval:
|
| 281 | # Special case: declare -A A=() is OK. The () is changed to mean an empty
|
| 282 | # associative array.
|
| 283 | if rval.tag() == value_e.BashArray:
|
| 284 | array_val = cast(value.BashArray, rval)
|
| 285 | if len(array_val.strs) == 0:
|
| 286 | # mycpp limitation: NewDict() needs to be typed
|
| 287 | tmp = NewDict() # type: Dict[str, str]
|
| 288 | return value.BashAssoc(tmp)
|
| 289 | #return value.BashArray([])
|
| 290 |
|
| 291 | if rval.tag() != value_e.BashAssoc:
|
| 292 | e_usage("Got -A but RHS isn't an associative array",
|
| 293 | loc.Word(blame_word))
|
| 294 |
|
| 295 | return rval
|
| 296 |
|
| 297 |
|
| 298 | class Readonly(vm._AssignBuiltin):
|
| 299 |
|
| 300 | def __init__(self, mem, errfmt):
|
| 301 | # type: (Mem, ui.ErrorFormatter) -> None
|
| 302 | self.mem = mem
|
| 303 | self.errfmt = errfmt
|
| 304 |
|
| 305 | def Run(self, cmd_val):
|
| 306 | # type: (cmd_value.Assign) -> int
|
| 307 | arg_r = args.Reader(cmd_val.argv, locs=cmd_val.arg_locs)
|
| 308 | arg_r.Next()
|
| 309 | attrs = flag_util.Parse('readonly', arg_r)
|
| 310 | arg = arg_types.readonly(attrs.attrs)
|
| 311 |
|
| 312 | if arg.p or len(cmd_val.pairs) == 0:
|
| 313 | return _PrintVariables(self.mem,
|
| 314 | cmd_val,
|
| 315 | attrs,
|
| 316 | True,
|
| 317 | builtin=_READONLY)
|
| 318 |
|
| 319 | for pair in cmd_val.pairs:
|
| 320 | if pair.rval is None:
|
| 321 | if arg.a:
|
| 322 | rval = value.BashArray([]) # type: value_t
|
| 323 | elif arg.A:
|
| 324 | rval = value.BashAssoc({})
|
| 325 | else:
|
| 326 | rval = None
|
| 327 | else:
|
| 328 | rval = pair.rval
|
| 329 |
|
| 330 | rval = _ReconcileTypes(rval, arg.a, arg.A, pair.blame_word)
|
| 331 |
|
| 332 | # NOTE:
|
| 333 | # - when rval is None, only flags are changed
|
| 334 | # - dynamic scope because flags on locals can be changed, etc.
|
| 335 | _ExportReadonly(self.mem, pair, state.SetReadOnly)
|
| 336 |
|
| 337 | return 0
|
| 338 |
|
| 339 |
|
| 340 | class NewVar(vm._AssignBuiltin):
|
| 341 | """declare/typeset/local."""
|
| 342 |
|
| 343 | def __init__(self, mem, procs, exec_opts, errfmt):
|
| 344 | # type: (Mem, state.Procs, optview.Exec, ui.ErrorFormatter) -> None
|
| 345 | self.mem = mem
|
| 346 | self.procs = procs
|
| 347 | self.exec_opts = exec_opts
|
| 348 | self.errfmt = errfmt
|
| 349 |
|
| 350 | def _PrintFuncs(self, names):
|
| 351 | # type: (List[str]) -> int
|
| 352 | status = 0
|
| 353 | for name in names:
|
| 354 | if self.procs.GetShellFunc(name):
|
| 355 | print(name)
|
| 356 | # TODO: Could print LST for -f, or render LST. Bash does this. 'trap'
|
| 357 | # could use that too.
|
| 358 | else:
|
| 359 | status = 1
|
| 360 | return status
|
| 361 |
|
| 362 | def Run(self, cmd_val):
|
| 363 | # type: (cmd_value.Assign) -> int
|
| 364 | arg_r = args.Reader(cmd_val.argv, locs=cmd_val.arg_locs)
|
| 365 | arg_r.Next()
|
| 366 | attrs = flag_util.Parse('new_var', arg_r)
|
| 367 | arg = arg_types.new_var(attrs.attrs)
|
| 368 |
|
| 369 | status = 0
|
| 370 |
|
| 371 | if arg.f:
|
| 372 | names = arg_r.Rest()
|
| 373 | if len(names):
|
| 374 | # This is only used for a STATUS QUERY now. We only show the name,
|
| 375 | # not the body.
|
| 376 | status = self._PrintFuncs(names)
|
| 377 | else:
|
| 378 | # Disallow this since it would be incompatible.
|
| 379 | e_usage('with -f expects function names', loc.Missing)
|
| 380 | return status
|
| 381 |
|
| 382 | if arg.F:
|
| 383 | names = arg_r.Rest()
|
| 384 | if len(names):
|
| 385 | status = self._PrintFuncs(names)
|
| 386 | else:
|
| 387 | # bash quirk: with no names, they're printed in a different format!
|
| 388 | for func_name in self.procs.ShellFuncNames():
|
| 389 | print('declare -f %s' % (func_name))
|
| 390 | return status
|
| 391 |
|
| 392 | if arg.p: # Lookup and print variables.
|
| 393 | return _PrintVariables(self.mem, cmd_val, attrs, True)
|
| 394 | elif len(cmd_val.pairs) == 0:
|
| 395 | return _PrintVariables(self.mem, cmd_val, attrs, False)
|
| 396 |
|
| 397 | if not self.exec_opts.ignore_flags_not_impl():
|
| 398 | if arg.i:
|
| 399 | e_usage(
|
| 400 | "doesn't implement flag -i (shopt --set ignore_flags_not_impl)",
|
| 401 | loc.Missing)
|
| 402 |
|
| 403 | if arg.l or arg.u:
|
| 404 | # Just print a warning! The program may still run.
|
| 405 | self.errfmt.Print_(
|
| 406 | "Warning: OSH doesn't implement flags -l or -u (shopt --set ignore_flags_not_impl)",
|
| 407 | loc.Missing)
|
| 408 |
|
| 409 | #
|
| 410 | # Set variables
|
| 411 | #
|
| 412 |
|
| 413 | if cmd_val.builtin_id == builtin_i.local:
|
| 414 | which_scopes = scope_e.LocalOnly
|
| 415 | else: # declare/typeset
|
| 416 | if arg.g:
|
| 417 | which_scopes = scope_e.GlobalOnly
|
| 418 | else:
|
| 419 | which_scopes = scope_e.LocalOnly
|
| 420 |
|
| 421 | flags = 0
|
| 422 | if arg.x == '-':
|
| 423 | flags |= state.SetExport
|
| 424 | if arg.r == '-':
|
| 425 | flags |= state.SetReadOnly
|
| 426 | if arg.n == '-':
|
| 427 | flags |= state.SetNameref
|
| 428 |
|
| 429 | if arg.x == '+':
|
| 430 | flags |= state.ClearExport
|
| 431 | if arg.r == '+':
|
| 432 | flags |= state.ClearReadOnly
|
| 433 | if arg.n == '+':
|
| 434 | flags |= state.ClearNameref
|
| 435 |
|
| 436 | for pair in cmd_val.pairs:
|
| 437 | rval = pair.rval
|
| 438 | # declare -a foo=(a b); declare -a foo; should not reset to empty array
|
| 439 | if rval is None and (arg.a or arg.A):
|
| 440 | old_val = self.mem.GetValue(pair.var_name)
|
| 441 | if arg.a:
|
| 442 | if old_val.tag() not in (value_e.BashArray,
|
| 443 | value_e.SparseArray):
|
| 444 | rval = value.BashArray([])
|
| 445 | elif arg.A:
|
| 446 | if old_val.tag() != value_e.BashAssoc:
|
| 447 | # mycpp limitation: NewDict() needs to be typed
|
| 448 | tmp = NewDict() # type: Dict[str, str]
|
| 449 | rval = value.BashAssoc(tmp)
|
| 450 |
|
| 451 | lval = LeftName(pair.var_name, pair.blame_word)
|
| 452 |
|
| 453 | if pair.plus_eq:
|
| 454 | old_val = sh_expr_eval.OldValue(lval, self.mem,
|
| 455 | None) # ignore set -u
|
| 456 | # When 'typeset e+=', then rval is value.Str('')
|
| 457 | # When 'typeset foo', the pair.plus_eq flag is false.
|
| 458 | assert pair.rval is not None
|
| 459 | rval = cmd_eval.PlusEquals(old_val, pair.rval)
|
| 460 | else:
|
| 461 | rval = _ReconcileTypes(rval, arg.a, arg.A, pair.blame_word)
|
| 462 |
|
| 463 | self.mem.SetNamed(lval, rval, which_scopes, flags=flags)
|
| 464 |
|
| 465 | return status
|
| 466 |
|
| 467 |
|
| 468 | # TODO:
|
| 469 | # - It would make more sense to treat no args as an error (bash doesn't.)
|
| 470 | # - Should we have strict builtins? Or just make it stricter?
|
| 471 | # - Typed args: unset (mylist[0]) is like Python's del
|
| 472 | # - It has the same word as 'setvar', which makes sense
|
| 473 |
|
| 474 |
|
| 475 | class Unset(vm._Builtin):
|
| 476 |
|
| 477 | def __init__(
|
| 478 | self,
|
| 479 | mem, # type: state.Mem
|
| 480 | procs, # type: state.Procs
|
| 481 | unsafe_arith, # type: sh_expr_eval.UnsafeArith
|
| 482 | errfmt, # type: ui.ErrorFormatter
|
| 483 | ):
|
| 484 | # type: (...) -> None
|
| 485 | self.mem = mem
|
| 486 | self.procs = procs
|
| 487 | self.unsafe_arith = unsafe_arith
|
| 488 | self.errfmt = errfmt
|
| 489 |
|
| 490 | def _UnsetVar(self, arg, location, proc_fallback):
|
| 491 | # type: (str, loc_t, bool) -> bool
|
| 492 | """
|
| 493 | Returns:
|
| 494 | bool: whether the 'unset' builtin should succeed with code 0.
|
| 495 | """
|
| 496 | lval = self.unsafe_arith.ParseLValue(arg, location)
|
| 497 |
|
| 498 | #log('unsafe lval %s', lval)
|
| 499 | found = False
|
| 500 | try:
|
| 501 | found = self.mem.Unset(lval, scope_e.Shopt)
|
| 502 | except error.Runtime as e:
|
| 503 | # note: in bash, myreadonly=X fails, but declare myreadonly=X doesn't
|
| 504 | # fail because it's a builtin. So I guess the same is true of 'unset'.
|
| 505 | msg = e.UserErrorString()
|
| 506 | self.errfmt.Print_(msg, blame_loc=location)
|
| 507 | return False
|
| 508 |
|
| 509 | if proc_fallback and not found:
|
| 510 | self.procs.EraseShellFunc(arg)
|
| 511 |
|
| 512 | return True
|
| 513 |
|
| 514 | def Run(self, cmd_val):
|
| 515 | # type: (cmd_value.Argv) -> int
|
| 516 | attrs, arg_r = flag_util.ParseCmdVal('unset', cmd_val)
|
| 517 | arg = arg_types.unset(attrs.attrs)
|
| 518 |
|
| 519 | argv, arg_locs = arg_r.Rest2()
|
| 520 | for i, name in enumerate(argv):
|
| 521 | location = arg_locs[i]
|
| 522 |
|
| 523 | if arg.f:
|
| 524 | self.procs.EraseShellFunc(name)
|
| 525 |
|
| 526 | elif arg.v:
|
| 527 | if not self._UnsetVar(name, location, False):
|
| 528 | return 1
|
| 529 |
|
| 530 | else:
|
| 531 | # proc_fallback: Try to delete var first, then func.
|
| 532 | if not self._UnsetVar(name, location, True):
|
| 533 | return 1
|
| 534 |
|
| 535 | return 0
|
| 536 |
|
| 537 |
|
| 538 | class Shift(vm._Builtin):
|
| 539 |
|
| 540 | def __init__(self, mem):
|
| 541 | # type: (Mem) -> None
|
| 542 | self.mem = mem
|
| 543 |
|
| 544 | def Run(self, cmd_val):
|
| 545 | # type: (cmd_value.Argv) -> int
|
| 546 | num_args = len(cmd_val.argv) - 1
|
| 547 | if num_args == 0:
|
| 548 | n = 1
|
| 549 | elif num_args == 1:
|
| 550 | arg = cmd_val.argv[1]
|
| 551 | try:
|
| 552 | n = int(arg)
|
| 553 | except ValueError:
|
| 554 | e_usage("Invalid shift argument %r" % arg, loc.Missing)
|
| 555 | else:
|
| 556 | e_usage('got too many arguments', loc.Missing)
|
| 557 |
|
| 558 | return self.mem.Shift(n)
|